Archive for the 'flexography' Category

#33: Thoughts on GRACoL 7 and Standards in General

Published
by
Jim Raffel
on May 4, 2006
in CGATS, GRACoL, blogging, conferences, flexography, guidelines and specification
. 1 Comment

Sunday, Monday, and Tuesday of this week I was in Louisville at the FFTA Annual Forum & INFO*FLEX exhibition.  It was my first time attending this event and I was impressed.  We even got to spend Tuesday evening at the Six Flags Kentucky Kingdom theme park in Louisville.  I must say it was fun not having to wait in line for any of the rides (the park was closed to the public).

I was busy assisting one of our distributors (ColorManagement.com) with booth duty Sunday and Monday, but I did manage to attend several technical sessions focused on Color Management Tuesday.  One of these sessions was about the still fairly new Printing Across Boarders (PAB) initiative.  At the urging of Adam Dewitz over at Printmode.net I resumed receiving e-mail from the [pab] forum several weeks ago, so was interested to hear what was happening.

The primary focus of the presentation by Gerald Gerlach of Integrity Graphics was the GRACoL 7 (G7) methodology.  It was during this presentation, and over the subsequent 24 hours that I began to solidify my current overall feelings about G7 and more importantly about graphic arts standards in general.

For my entire career in the graphic arts (more than 20 years now) I have nibbled at the edges of the standards community.  I have always found it fascinating and have felt I had something to contribute.  While my main role in life is now selling, I am still a pretty fair graphic arts technician when I need to be.  I have not been more involved in the standards community for one reason; time.  Those who carry the vast majority of the standards load in this industry do so as volunteers.  While they may be on a company payroll somewhere I assure that only a very small percentage are paid to do only standards work.

These people give up evenings, weekends, and other valuable personal time so we can have graphic arts standards.  I wish to say to all of you (and you know who you are) THANK YOU!  So, perhaps instead of standing on the sidelines and criticizing (constructive or otherwise) all of us should be saying “how can we help you.”

While I do not completely agree with the G7 methodology, I do agree it is a step forward.  I believe this because our competition in the Graphic Arts industry is not other printers.  It is other communication mediums.   Can you imagine television succeeding without any standards?  Can you imagine the internet succeeding without any standards?

We as an industry need the ability to print an image consistently anywhere in the world.  This is the true goal of G7 as far as I can tell.  While I feel in the case of many printers this means you must “dumb down “ your press, the trade off for regional, national, or international print buyer makes this consequence of the methodology worth while.  Any printer can still apply their “secret sauce” technology to specialty jobs.  Just because you can print to G7 does not mean you must print to G7.

In conclusion, I want to ask the working members of BRIDGS, CGATS, FIRST, GRACoL, SNAP, & SWOP….How can I help?

#22: Why 95 is more than 100

Published
by
Jim Raffel
on January 12, 2006
in TVI (Dot Gain), density and flexography
. 0 Comments

When printing with the flexographic (Flexo) printing process it is not uncommon for the 95-99% tone patches to have reported dot areas greater than 100%. While visiting a ColorMetrix customer last week I got a refresher course on why this phenomenon occurs. So, I thought I would start the year of golden nuggets off with this flexographic 101 information.

Because Flexo is a relief printing process, the actual printing surface is raised. So, a solid tone area would look like a raised rubber stamp block. A 95% tone area, however, would have small dimples covering the surface of the area. Flexo makes use of a viscous ink which is transferred to the plate by an anilox roller.

Unlike the offset process which lays down a relatively uniform ink film thickness on the entire printing plate, the combination of an anilox roller and a dimpled 95% tone area allows a Flexo plate to carry more ink in some areas. The dimples or little valleys get filled with ink by the anilox and then when the ink is transferred to the substrate the additional ink in the dimple gets piled on top of the rest of the ink laid down by the plate.

Combine this with the fact that in Flexo printing it is not uncommon for a 95% tone area to already be printing as a solid due to the pressure of the “rubber stamp” nature of the process. Before reading this far many of you probably had been questioning my math skills. By this point, however, it should be clear that if you print more density in a “planned” 95% tone area than in a “planned” solid tone area, you will end up with a calculated dot area greater than 100%.

There is some real value in understanding at what tone value this maximum density occurs. While previous releases of ColorMetrix displayed dot areas greater than 100% we seem to have fixed this “bug” at some point. We will have a new release of ColorMetrix built and ready for distribution in the coming weeks, and you will once again be able to display dot percentages greater than 100% from a set of ColorMetrix measurements.